I had $3.00 my mom gave me $10.00
my dad gave me $30.00
my aunt and uncle gave me $100.00.
i had another $7.00
how much did I have?

Before your family gave you money, you had $10.00 ($7.00 that you had + $3.00 that you had)

Now, you have $150.00 (the $10.00 you had plus $10.00 ($20) plus $30.00 ($50) plus $100.00 ($150)